<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  <script>
    let age = +prompt('请输入您的年龄：')
    alert(`据我估计，五年后，您可能${age + 5}岁了`)
  </script>
</body>
</html>